The prologue begins by addressing “Fortune,” wishing away the two hours that the play will take to perform and hoping to do justice to its author. It announces the play’s scene, London, with “no country’s mirth is better than our own.” It also is the best place to find whores and lowlifes. Many sorts of people, of many different humors, are to grace the stage. The writer, apparently, wishes not to attack these characters and the real people they represent, but to “better” them—the traditional aim of satire. He also hopes that no one will be displeased with the “fair correctives” the play is about to offer. He alerts us that no one who can “apply” lessons has anything to fear.
The prologue finishes with an ambiguous metaphor: there are people who can sit near to “the stream” to find things “they think or wish were done.” Yet these involve such “natural follies” that even the people who “do” them might see them and not “own” them—not recognize the follies as their own.
This in many ways is a traditional prologue, appearing in verse and apologizing for the shortcomings of the play and its writing—and thereby begging the audience’s endurance, while setting out something of what the play is about to treat. In this instance, it addresses the London and the sort of characters the play is to depict.
Most interesting perhaps is the warning that people watching the play will have to “apply” to understand it: The play is going to be a symbol, a metaphor; its characters must be applied to the real world. It is to attempt Hamlet’s “holding the mirror up to nature,” and we must, by examining the mirror, figure out what it is reflecting, what kinds of things it is designed to reflect.
The final image of the stream is variously interpretable. What it seems most clearly to mean is the plot, the stream of events, and those who watch intently will see that The Alchemist will reflect things very close to home, things that might otherwise (or may yet) be unrecognizable in their own lives. The audience is thus the subject of the satire; this is a play about them. In many ways, as later sections show, the play can be read as bearing out that judgment.
We do not know for certain if the prologue would have been spoken in theatrical performance or if it was a feature of the play preserved only in written editions, nor do we know in this case which of the characters, if any, would have spoken it. It is most likely to be Lovewit, master of the “house” (both in the Blackfriars and the theater itself), but there are various scholarly opinions about why, for example, Subtle or Face might be more appropriate speakers.